General Neuro Questions For Final Flashcards
Are the CR and the UCR different responses?
No. Same response to a different stimulus.
What is the Hebb rule?
Synapses active at the same time are strengthened over time
signs of this in rats: thicker cortex, more glial cells, more AChE
Describe the neural model of classical conditioning
The synapse is strengthened when an incoming action potential occurs at the same time as a postsynaptic action potential
Define reinforcement
A reinforcement makes a behavior more likely to occur in the future.
Define punishment.
A punishment makes a behavior less likely to occur in the future.
What is the “reward circuit”?
The Mesolimbic dopamine pathway. VTA->nucleus accumbens->amygdala->septum
Describe the mesocortical dopamine system.
VTA->PFC
What are the three phases of biological memory processes?
- Induction. Initiates modification processes
- Maintenance. The mechanisms that cause the modifications to stay
- Expression. How the modification is ultimately expressed.
What are the components of the hippocampus?
Dentate gyrus
Subicular complex
Hippocampus proper (CA regions)
Where does the entorhinal cortex receive input from?
- Amygdala
- Limbic cortex of the medial temporal lobe
- Association vortices (sensory, motor)
These may project directly, or via the perirhinal cortex, or parahippocampal cortex.
Where does the entorhinal cortex project to?
CA1, CA3, dentate gyrus
Where does the hippocampus output to?
Entorhinal, perirhinal, parahippocampal cortices
The primary output of the hippocampus comes from
The CA1 region and the subiculum
LTP requires:
Rapid stimulation of the perforant path
Activation of synapses and depolarization of the postsynaptic membrane
Activation of hippocampal NMDA receptors
Describe the process of LTP.
- Glutamate is released by presynaptic neuron
- AMPA receptor (not exotic) binds glutamate, allows Na+ to enter, depolarizers membrane
- NMDA (exotic) kicks off Mg2+ ion, Ca2+ enters cell
- Ca2+ entry triggers CAM-KII pathway cascade
- Phosphorylation of AMPA receptors (increased sensitivity/density)
- Production of NO synthase, arginine converted to NO
- NO diffuses into presynaptic cell, causes increase in glutamate release via cGMP, altered synaptic structure
LTP may result from:
Increased number of new AMPA receptors
Alternation of synaptic structures
What are the properties of LTP?
- Co-operativity–multiple axons acting simultaneously produce more LTP than a single axon
- Associativity–pairing a weak input with a strong one can strengthen the response to the weak input
- Facilitation–neurons that work together have stronger synapses.
- It occurs in the hippocampus and cerebral cortex.
What are physical changes to the synapse involved in LTP?
- Forming collaterals
- Increased NT release
- More postsynaptic receptors
- Thicker/smaller neck of dendritic spine
- Perforated synapse formation
- ^ transport
- ^ size/area of terminal
- ^ number of synaptic vesicles
- ^ density of contact zones
- ^ size/number dendritic spines
- ^ protein transport for spine construction
- Lowered synaptic cleft size
Loss of CA1 neurons results in:
Anterograde amnesia
Damage to the hippocampal formation causes:
~10 years of retrograde amnesia
If medial temporal lobe also damaged, ~30 years
Pyramidal neurons project:
From forebrain to hindbrain
Metabolic disturbance of the CA1 region can result in
Excess glutamate release, which causes a buildup of calcium, leading to cell death (anterograde amnesia)
Damage to perirhinal and parahippocampal cortices can result in:
Anterograde amnesia
Pyramidal neurons are mainly in the:
Hippocampus
Removing PKC takes away
Place cell field stability
Knocking out NMDAR1 receptor disrupts
Spatial memory
Anticholinergics do what to learning:
Impair it
Early in Alzheimer’s disease, neurons that secrete ___ are lost
ACh
How are ACh neurons linked to memory?
Release of ACh makes cortical neurons more sensitive to tones that have been previously paired with arousing stimuli.
Where do ACh neurons (in learning) project to and from?
From the nucleus basalis to the neocortex
From the medial septum to the hippocampus
Damage to the lateral interpositus nucleus of the cerebellum causes:
Complete loss of the conditioning response.
Suppression of the red nucleus causes:
A lack of response, but not a lack of actual learning
Can brain damage impair LTM and STM independently?
Yes
Why does emotional experience enhance memory storage?
Emotional experiences activate sympathetic NS, which releases epinephrine from medulla.
Epinephrine stimulates vagus nerve and raises blood glucose levels. This increases production/release of ACh and NE.
How does NE improve memory storage?
NE increases stimulus salience by boosting signal:noise ratio.
The bGH mice were ____ and learned ____.
Bigger and learned slower.
The GHA mice were ____ and learned _____.
Smaller and learned faster.
